Putty knife



April 26, 1955 J. L. s'rREFLiNG PUTTY KNIFE Filed Feb. 23, 1952 United States Patent PUTTY KNIFE John L. Strefling, Chicago, Ill.

Application February 23, 1952, Serial No. 273,099

4 Claims. (Cl. 183.5)

My invention relates to building maintenance and includes among its objects and advantages increased speed and convenience in installing panes of glass or the like in conventional window sash with the joint around the edge of the glass sealed with putty.

In the accompanying drawing:

Figure l is an elevation of a window sash with the bottom edge puttied and the right-hand vertical edge being puttied;

Figure 2 is a similar view, indicating the position of the tool at the end of the stroke for puttying the right vertical side;

Figure 3 is a view of a window sash with no glass in it, 1illustrating the removal of old putty with the same too Figure 4 is a partial section, as on line 4-4 in Figure 1.

Figure 5 is a full-size plan view of the tool itself; and

Figure 6 is an edge view of the tool itself.

In the embodiment of the invention selected for illustration, the tool includes a conventional handle formed in two halves 10 and 12 and fastened together with the shank 14 between them by three rivets 16. The shank itself is of steel and is integral with the blade 18. As clearly shown in Figure 6, the blade tapers from a thickness next the handle equal to that of the shank, to a thickness about one-half as great at the extreme tip 20. The advantages of the tool reside principally in the shape and configuration best shown in Figure 5. The tip is almost, but not quite, in line with the axis of the handle. In the illustrative embodiment, with a blade four inches long, the tip is offset only three-sixteenths of an inch to the right of the handle axis, as seen in Figure 5. The edge leading to the tip on the right is inclined away from the handle axis about fifteen degrees for a distance of about one and one-half inches. This enables the user, as best indicated in Figure 3, to push the tip 20 along under old dry putty indicated at 22 in cleaning out the sash 24 preparatory to inserting a new pane of glass. The right side edge portion 26 leading up to the point 20 will have contact substantially throughout its length with the lateral wall 28 of the rabbet in the sash, to provide good guidance for the tool and to scrape the wall 28 clean, but the handle portion is over to the left far enough to leave clearance for the fingers of the user so that he can move the handle up and down a little when he encounters an old tack or a hard spot in the putty, without bringing his fingers down against the sash where he would cut his knuckles on the edges of the rabbet. During this operation the steeply inclined left edge 30 is a mere deflector for the pieces 31 of dislodged putty.

In a new sash, or an old sash from which the putty has been cleaned out, installation is done in the conventional way. The glass pane 32 is laid in the rabbet with its edge abutting the underlying flange 34 of the rabbet. At this time there may be a slight clearance as indicated at 36 a in Figure 4 between one or both edges of the glass and the sidewall 28 of the rabbet. A plurality of conventional triangular tacks 38 are then driven into the sidewall 28 of the rabbet in the position indicated in Figure 4 where they overlie the edge of the glass and hold it in place with considerable mechanical strength but without a water-tight joint. 7

The next step is the application of the putty. The inclined edge 30 of the tool makes an angle of substantially forty degres with the handle axis and ends at 40 in a square point defined by a re-entrant edge portion 42,

2,706,831 Patented Apr. 26, 1955 "ice which makes a right angle with the edge portion 30. The points at 40 and 20 are preferably rounded off. A radius of one-sixteenth of an inch is about right for the point 20 and a radius of about three-thirty-seconds of an inch is about right for the point 40.

The length of the re-entrant edge 42 is such that, when applied to a sash of conventional dimensions, it is long enough to extend across the diagonal face of the finished filling 44, as best indicated in Figure 4, and in that angular position to reach up to the top of the sidewall 28. Beyond the inner end of the re-entrant portion 42 the edge turns outwardly again to define a guide portion 46. The angle between the portions 42 and 46 is about one hundred five degrees, and is such that the edge portion 46 can lie substantially in the plane of the top face 48 of the sash 24 when the tool is in the position of Figures 1, 2, and 4.

Beyond the guide portion 46 the remainder of the blade is a mere structural connection to the handle and the angularity of the edge is substantially immaterial. The same consideration applies to the right-hand edge of the blade from the rear end of the outer portion 26 all the way back to the handle.

In putting in new putty the operator fashions a spherical or cigar-shaped wad of putty, as his acquired habits may dictate, and places it in the rabbet at one corner of the sash and sets the blade over it in the position indicated in Figure 4 and pushes it away from the starting corner. In Figure l I have indicated the bottom side of the sash already puttied at 50 and most of the right side at 52. As the blade is pushed along toward the remote corner of the sash the little gob of putty indicated at 54 in Figure 1 may be replenished so that the filling 44 is completed. This necessarily involves a slight excess which will flow up onto the face 48 and be pushed over a little laterally to form a row of small gobbets indicated at 56 in Figures 1 and 2. Because the crosssection of the putty at 54 where it is first entrapped between the blade and the rabbet is of the order of magnitude of four times as great as the cross-section of the finished filling 44 and because the blade surface sliding along and squeezing the putty into the filling and forward in front of the knife lies at a very acute angle, I have found that after a little practice it is possible to hold the knife in the right hand and slide it the entire length of one side of the sash with an almost uninterrupted movement while the left hand is kept busy feeding additional putty in, in front of the knife.

Another common technique is to butter in enough putty along the length of the rabbet, to form the complete finished filling. Then when the knife slides along, the operator need pay attention to nothing except keeping the knife at exactly the right angle. On substantial jobs it works well for one man to fasten in the glass and butter the rabbets. Another workman can come along a half-hour later and strike the fillings smooth with a putty knife. The short exposure starts to build a little hardness in the putty and a skillful man with the knife can do a better job than when the putty is fresh.

The application of the putty at 52 in Figures 1 and 2 ends when the knife reaches ,the position of Figure 2, but a short end portion directly at the corner is not completely finished. After the tool reaches the position of Figure 2 the operator rotates it around the abutment of the top edge of the wall 28 in the crotch between edge portions 42 and 46 as a fulcrum until the tip 20 has come over in line with the heel 40. This squeezes a final small increment of putty out on top of the sash and subsequent movement of the knife blade in the plane it then occupies slides it diagonally up and away, to leave a completely finished end portion. Finishing the end in this way occurs three times, but when the end of the fourth filling is reached the toe 20 comes up to the beginning of the first filling 50 and at this final joint the operator needs to stop about three-eighths of an inch short of the position of Figure 2. He can then pivot the knife, as before, and after the toe 20 and heel 40 are in line, the movement of withdrawal needs to be diagonally forward and upward and will require a moment of careful attention to finish the last corner joint.

Others may readily adapt the invention for use under various conditions of service by employing one or more of the novel features disclosed or equivalents thereof.

For maximum manual comfort the side of the handle adjacent the lateral point 40 may be curved, with the center bowed in up to about a quarter of an inch. This can be done by curving the handle axis, so that the opposite side is convex and snuggles in the palm of the hand, or the axis can be left straight.

As at present advised, with respect to the apparent scope of my invention, I desire to claim the following subject matter.

1. A putty knife comprising, in combination: an elongated handle having a longitudinal axis; a blade operatively assembled with said handle; the projecting fraction of said blade being tapered in thickness with its thin end remote from said handle; said blade, in plan view, presenting a forwardly directed point; a first, flaring, left edge portion inclined rearwardly and outwardly at an angle of about forty degrees to the handle axis; a second, flaring edge portion to the right of said point inclined rearwardly and outwardly at an angle of about fifteen degrees to the handle axis; a laterally directed point at the rear end of said first flaring left edge portion; a third, re-entrant edge portion behind said laterally directed point; said third portion lying at substantially right angles to said first portion; a fourth, flaring, left edge portion behind said third edge portion; said third and fourth edge portions defining a crotch having an opening of substantially one hundred five degrees.

2. A putty knife comprising, in combination: an elongated handle having a longitudinal axis: a blade operatively assembled with said handle; said blade, in plan view, presenting a forwardly directed point; a first, flaring, left edge portion inclined rearwardly and outwardly at an angle of about forty degrees to the handle axis; a second, flaring edge portion to the right of said point inclined rearwardly and outwardly at an angle of about fifteen degrees to the handle axis; a laterally directed point at the rear end of said first flaring left edge portion; a third, re-entrant edge portion behind said laterally directed point; said third portion lying at substantially right angles to said first portion; a fourth, flaring left edge portion behind said third edge portion; said third and fourth edge portions defining a crotch having an opening of substantially one hundred five degrees.

3. In a putty knife of the type having an axis and comprising a handle and a blade projecting axially from one end of said handle; a blade having a pointed end; said blade having a flaring edge portion facing forwardly and laterally and extending back from said point at an angle of substantially forty degrees to the knife axis; a re-entrant edge portion adjoining the rear end of said flaring edge portion and facing rearwardly and laterally at an angle of substantially fifty degrees to the axis; and a flaring edge portion adjoining the rear end of said re-entrant edge portion and facing forwardly and outwardly at an angle of about twenty-five degrees to the axis.

4. In a putty knife according to claim 3; a flaring edge portion, opposite said first mentioned flaring edge portion, facing forwardly and laterally and extending back from said point at an angle of substantially fifteen degrees to the knife axis.

References Cited in the file of this patent UNITED STATES PATENTS 123,497 McCarraher Feb. 6, 1872 634,621 Jones Oct. 10, 1899 745,162 Donnelly Nov. 24, 1903 2,261,063 Joyce Oct. 28, 1941 2,322,359 I-Iirschhorn June 22, 1943 

